5-Hydroxyindoleacetic Acid (5-HIAA), 24-Hour Urine, with Creatinine

Test Code
5-HIAA 24HR Urine (39625)

Quest Code
39625

CPT Codes
83497, 82570

Includes
CPT code 81050 may be added at an additional charge for volume measurement

Preferred Specimen
10 mL 24-hour urine with 25 mL 6N HCl collected in a 24-hour urine container

Patient Preparation
Patient should avoid food high in indoles: Avocados, banana, tomato, plum, walnut, pineapple, and eggplant.

Minimum Volume
5 mL

Instructions
Collect 24-hour urine with 25 mL of 6N HCl to maintain a pH below 3. Urine without preservative is acceptable if pH is below 6 and the sample is shipped frozen. Keep urine refrigerated during collection if preservative is not used. Record 24-hour urine volume on test request form and urine vial. Record patients age on test request form and urine vial.

Transport Temperature
Room temperature

Specimen Stability
Room temperature: 7 days
Refrigerated: 30 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
pH >3.0 and received unfrozen

Methodology
High Performance Liquid Chromatography (HPLC) • Electrochemical Detection

This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Tue, Thu-Fri

Report Available
3 to 7 Day(s)

Limitations
Patients with renal disease may display falsely decreased results. Urinary 5-HIAA is increased in patients with malabsorption disorders who also display a larger concentration of urinary tryptophan metabolites. Urinary 5-HIAA is increased in patients with intestinal obstruction and with some noncarcinoid islet cell tumors. Carcinoid syndrome may not cause elevated results, especially if the patient does not have diarrhea.

Reference Range
See Laboratory Report

Clinical Significance
5-HIAA is the end product of serotonin (5-hydroxytryptophan) and tyrptophan metabolism. Patients with carcinoid tumors of the midgut, e.g., ileum, produce high concentrations of 5-HIAA. Patients with carcinoid tumors of the foregut and hindgut may produce little or no 5-HIAA or do so intermittently.

Performing Laboratory
Quest Diagnostics Nichols Institute San Juan Capistrano
33608 Ortega Hwy
San Juan Capistrano, CA 92675-2042



The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.